【摘 要】
:
The vulcanization mechanism remains unclear due to the difficulty of characterization and the complexity of the vulcanization systems.In this work,a series of epoxy model systems were used to study th
【机 构】
:
Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Ch
【出 处】
:
京津冀粘接技术研讨会暨北京粘接学会第26届学术年会
论文部分内容阅读
The vulcanization mechanism remains unclear due to the difficulty of characterization and the complexity of the vulcanization systems.In this work,a series of epoxy model systems were used to study the sulfur cleavage behavior,from which the study process of the vulcanization mechanism was significantly simplified and a brand new sulfur-only vulcanization mechanism was revealed by the FTIR and DSC analysis.Our studies suggest that thiyl radicals derived from the homolytic cleavage of sulfur play the dominant role in the vulcanization,while the heterolytic fission of sulfur cannot occur as expected because this reaction needs 200 ℃.Nevertheless,sulfur anions,which are easy to be understood derived from the heterolytic cleavage of sulfur,are actually transformed from the thioi groups that are produced through the reaction of thiyl radicals abstracting α-H atoms of allyl groups in rubber.And this maybe the reason that vulcanization mechanism remains controversial for centuries.
其他文献
This technique is a technique of repairing and moulding metal materials,including ceramic powder,metallic powder and ceramic material made from ceramic materials,and coating materials such as coating
橡胶沥青涂料与自粘卷材的复合防水做法是目前较为理想的组合方式。该做法已成功应用在很多实际工程当中,比如江西南昌象湖隧道、杭州白马湖数字电视产业园屋面等。这些工程在采用涂卷结合的同时,还引入了防水工程责任险制度,进一步保证了防水效果,至今没有出现渗漏。因此,橡胶沥青涂料与自粘卷材的复合防水系统为我们在解决建筑渗漏难题方面提供了很好的参考和借鉴。
环氧树脂碳纤维筋结合了环氧树脂与碳纤维优异的力学、物理、化学性,可以被广泛用来解决隧道、路面、桥面混凝土结构的抗压问题和抗震问题。其施工简便、优异的防腐蚀性和抗震性等优点使其在特殊领域逐步取代钢筋,并在建筑工程领域占据一席之地,同时我国也应该在碳纤维复合筋的生产工艺上不断创新发展,使得国内的生产水平能不断提高,稳定性不断增强。降低环氧树脂碳纤维复合筋的运用成本,才能使它在各个领域内得到更广泛的利用
本文简述了THC硼酚醛树脂的多功能性.用模压、层压不同工艺,在玻璃纤维、碳纤维和玄武岩纤维中的应用的力学性能、耐热性能,烧蚀性能和洁净阻燃性能.
本文把耐高温、耐烧蚀、洁净阻燃的THC系列硼酚醛树脂,通过与橡胶化学反应,得到一种新的聚合物RFB增韧性硼酚醛树脂,RFB树脂同时具有了耐高温、耐烧蚀、阻燃、增韧、防中子射线,五功能齐全的新聚合物.既可单独使用,又可作为固化环氧树脂.形成了五大功能的酚醛——环氧——橡胶三元体系,并产生交互反应,配比可调,性能各异的无数产物,使之自由过渡,打破了热固性、热塑性、酚醛、环氧、橡胶一系列的固有概念,使高
本文将着重介绍应用预应力碳纤维板加固系统进行加固的方法,体现该新型加固技术相较于普通碳纤维板加固的优势.文中以津晋高速某路段加固工程为例,说明了该加固技术用于高速公路加固的施工工艺及效果.
粘接技术的应用十分广泛,但其中的许多奥秘仍未揭开.许多实验事实得不到理论的证明,连起码的粘接性抽象不出来.此篇专门证明:在单搭接拉剪中,当搭接长度与厚度之比相等时,则二者的平均剪切强度也相等.许多有关粘接或胶粘剂的专著都有记载.
2.4-咪唑固化通用环氧有许多优点,获得了广泛的应用.但是其固化动力学的仔细研究未见报道.因为这个反应为三个连串的复杂反应,应用通常的方法无法得到分步的动力学参数.应用了DSC加浓度外推法,首先求出了不同配比的每毫克环氧的放热量为一常数,表明反应停留在第一步,然后再作动力学的计算.求出第一步反应的动力学参数,此后又求出来第二、第三步的动力学参数.创立了剪纸称重的动力学的公式,并首次发现了2.4-咪
本文介绍了利用国外所作的粘接全过程的破坏负荷与搭接长度的关系图,运用自然辩证法的思维模式,打破了拉伸力和剪切力的界限,突破经典材料力学的剪切虎克定律的束缚,创立非纯剪切的计算法,精确定义了粘接性,把四大类不同的客观物理量联系到一个微分方程中,解这个微分方程,得到一系列国内外没有的公式,并定量的证明国外的实验事实.并得到拉伸力(或压力)与剪切力互相渗透、转化的关系,揭露了剪切力的本质.
In this paper we present a new approach,called Two-Step-Functionalization approach to integrate electric conductivity function into structural adhesive bonds.A nylon textile is used for supporting pol